Can-top opening closure

ABSTRACT

A can-top opening closure is provided with a top wall from which extends downwardly depending legs adapted to engage with the upper surface of the can top adjacent the top opening. Centrally of the top wall is a downwardly depending body having a peripheral shape corresponding to that of the top opening. The body portion is either dimensioned to clear the edge of the can top defining the opening or be in frictional engagement therewith. A sealing lip is spaced downwardly from the top wall, extends outwardly of the body portion and is adapted to be inserted through the top opening and thereafter flexed and biased into sealing engagement with the inner surfaces of the can top adjacent the opening. The closure is provided with surfaces adapted to be engaged for purposes of facilitating the insertion and removal of the closure from the opening. This is also enhanced by the flexible and resilient one-piece, molded construction of the closure. The sealing relationship of the lip is optimized by locating this lip closer to the top wall than the lower edge of the downwardly depending legs which engage with the upper face of the can top thereby creating an upwardly directed biasing force for increasing the sealing pressure between the lip and the inner face of the can top adjacent the opening.

United States Patent 10583 [21 App]. No. 873,841 [22] Filed Nov. 4, i969 [45] Patented Nov. 23, 1971 [54] CAN-TOP OPENING CLOSURE 16 Claims, 14 Drawing Figs.

[52] U.S.Cl 220/60, 220/24, 220/25 [Sl] lnt.Cl ..B65d 43/10, B65d 39/00, 865d 41/00 [50] Field oiSearch 220/60, 24, DIG. l9;2l5/4l,47 [56] References Cited UNITED STATES PATENTS 2,546,672 3/1951 Le Clair 220/DlG. 19 3,229,478 l/l966 Alonso.... 220/60 UX 3,021,975 2/1962 Sarafinas. 220/60 3,332,572 7/1967 Green..

3,428,212 2/1969 Rohrlick Primary ExaminerGeorge T. Hall Attorney-Kane, Dalsimer, Kane, Sullivan and Kuruez and thereafter flexed and biased into sealing engagement with of the can top thereby creating an upwardly directed biasing force for increasing the sealing pressure between the lip and the inner face ofthe can top adjacent the opening.

CAN-TOP OPENING CLOSURE This application relates to can top opening closures of the type disclosed in issued U.S. Pat. No. 3,445,030, granted on May 20, 1969, for CAN CLOSURE PLUG."

In the design of a closure for a pop-top" can opening, it has been found that the most effective seal is obtained by firmly interengaging surfaces of the closure and the interior of the can top adjacent the opening. In order to optimize this seal, upwardly directed biasing forces are required especially in the absence of fluid pressurization within the can. At the same time, once the desired seal is obtained between the surfaces of the closure and the can top provisions must be made for preventing the closure from inadvertently or unintentionally popping out" or, otherwise being forced out of the opening particularly incident to the build up of gaseous pressure within the closure-sealed can.

Accordingly, it is a principal object of this invention to provide a closure possessing the above desirable properties and one which is of integral one-piece construction possessing flexibility and resiliency to facilitate manual insertion of the closure in sealing relationship across the can opening and manual removal therefrom to obtain access to the contents of the can interior.

The several aforenoted objects and advantages are attained and others will become more apparent from the following detailed description which is to be taken in conjunction with the accompanying drawings in which:

FIG. 1 is an exploded fragmentary perspective view of the upper portion of an open can and a closure incorporating the teachings of this invention, with this closure being shown in phantom in the preliminary stage of being manually inserted across the can-top opening to seal the can contents;

FIG. 2 is a similar view showing the closure fully inserted in position in sealing relationship across the can-top opening;

FIG. 3 is another view of this type showing the closure at the start of manual removal from the can-top opening with the phantom lines depicting finger pressure being applied to effect another form of closure manipulation to remove it from the can-top opening;

FIG. 4 is an enlarged bottom plan view of the closure;

FIG. 5 is a cross-sectional view taken along the line 55 of FIG. 4;

FIG. 6 is an enlarged cross-sectional view of the closure taken along the line 6-6 of FIG. 2 showing the closure in sealing relationship with the can-top opening and the manner in which the various parts of the closure are disposed in accomplishing this firm seal, the arrows representing the pressure points which contribute thereto;

FIG. 7 is a longitudinal sectional view taken along the line 7-7 of FIG. 6;

FIG. 8 is a partial sectional view of a modified form of top wall of a closure of this type;

FIGS. 9 to 14 are cross-sectional views similar to FIG. 5 showing other forms and configurations of closure incorporating the teachings of this invention.

Reference is now made to FIGS. 1-7 illustrating a preferred embodiment of closure which is adapted to be placed in removable sealing relationship across opening 22 defined by edges 24 in the top 26 of can 28. The can 28 may be of the type that is adapted to contain any type of liquid or beverage either carbonated or not. Once part of the contents of such containers has been consumed, it is oftentimes desirable to seal the partially consumed liquid particularly of the carbonated or gaseous type to minimize the chances of it becoming flat." In actual practice the opening 22 may assume one of many configurations and based on the commercially available pop-top cans, the openings will generally be narrower near the center of the can and progressively become larger as the periphery of the can top is approached. Closure 20 may assume a corresponding configuration, although other shapes are obviously within the purview of this invention. Generally a closure of this invention will include 'a top wall 30, body portion 32 and sealing lip 34.

The top wall is designed to present surfaces for facilitating the insertion and removal of the closure from the can-top opening and, at the same time, surfaces which are adapted to forcibly engage with the upper face of the can top for purposes of inducing an upwardly directed biasing force which urges the sealing lip 34 into finn engagement with the inner face of the can top 26. Towards this end, the top wall 30 is provided with a pair of opposed downwardly depending feet 40 and 42 the bottom edge of which is adapted to engage with the upper face 36 of the can top 26. In order to induce outward flexing of the sealing lip 34 and the upwardly directed biasing force urging the lip upwardly against the inner face 38 of the can top 26 the lower edge of the legs 40 and 42 extend below the upper edge of the lip 34. This provision is extremely important for purposes of assuring the sealing relationship between closure and can top to prevent leakage of the can contents as well as the entrapped carbonation or gases the escape of which would render the contained beverage fiat. The legs 40 and 42 may be interconnected or be of an interrupted nature. In this manner surfaces of the top wall 30 will be elevated to facilitate finger engagement for purposes of removal of the closure from the can opening.

The body portion 32 extends integrally from the top wall 30 in a downward direction and assumes a configuration essentially that of the can opening 22. In this connection, the dimensioning of the body portion 32 may be less than that of the opening 22 thereby providing a clearance with the opening edge 24. On the other hand, to add to the prevention of unintentional and accidental popping or removal of the closure 20 from the can opening 22, a frictional engagement or seal may be provided between the body portion 32 and the edge 24 by dimensioning and shaping the body portion 32 precisely equal to or larger than that of the opening 22. The body portion 32 includes an outer wall 44 which may be essentially nonnal to the top wall 30. Where desirable or practical, the body portion 32 may be cored and thus be tubular in nature having the interior recess 46. Provisions for this recess saves on material and, at the same time, does render the body portion more flexible.

The sealing lip 34 extends outwardly from the body portion 32 and is designed with sufficient flexibility to permit inward flexing of the lip to ride over the edges 24 of the can opening 22 when the closure is inserted. The lip 34 extends outwardly a sufiicient amount to permit engagement with the inner face 38 of the can top 26 when the lip has cleared the edge 24 of the can top. In this manner, the lip is forced into engagement with the inner face 38 of the can top 26. The sealing lip 34 of the embodiment of FIGS. 1-7 is defined by an upwardly and outwardly bevelled or flaring wall 48 and an inner wall 50 both extending from the lower end of the body portion 32. The angularity of each of these walls 48 and 50 are such that the outer edge 44 of the sealing lip 34 is thinner than the base 52. In this manner, the sealing lip is provided with flexibility adjacent the end of the edge 44 to permit clearance of the hole 22 when inserting the closure in place and also to create the desired seal between the inner wall 50 of the lip 34 and the inner wall 38 of the can top 26. The base 52, however, does furnish sufficient rigidity at this location to prevent the closure from popping out of the hole unintentionally particularly under internal pressure of the contents of the can. In the case of soda pop and other similar beverages, it is desired that the closure remain in place notwithstanding the pressure interiorly of the can. p

In utilizing the closure 20 of this invention following the formation of the opening 22 in the pop open can and consummation of part of the can contents, the individual has a number of optional or alternative procedures that may be followed in placing the closure in sealing relationship across the opening 22. In one procedure the closure 20 is lowered downwardly into the opening 22 so that the flared wall 48 extends into this opening. Thereafter sufiicient downward pressure is exerted on the upper face of the top wall 30 to have the sealing lip edge 44 clear the edge 24 of the can opening and be disposed in the can interior. The closure is then released and the lip 34 is biased against the inner wall 38. If a gaseous or carbonated beverage is included in the sealed can, the seal between the lip 34 and inner face 38 of the can is increased with time. When it is desired to remove the closure and obtain access to the contents of the can, a number of different manipulations of closure are possible for purposes of obtaining closure removal. In fact, any number of exposed surfaces of the top wall including legs and 42 may be pressed, pushed or gripped to pull or otherwise force the closure out of the opening 22. The elevated nature of the parts of the top wall 30 between the terminal side ends of the legs 40 and 42 facilitates the finger gripping of the closure at these locations. Another manner of inserting the closure 20 across the opening 22 is to slide and work the narrow end starting from the wider end of the open ing 22 to the narrower end thereof in directing the edge 24 between the lower face of the top wall 30 and edge 44 of the lip 34. It may be found that slight downward pressure facilitates this type of closure insertion and certainly when the narrower end of the closure registers with the narrow end of the opening 22, the wider end of the closure may have to be forcibly pushed downwardly to complete the seal of the cap opening at the wider end. In manipulating the closure 20 into position in this manner, it may be found expeditious to pinch or squeeze the legs 40 and 42 by means of finger pressure to bow the top wall 30 upwardly to form a concavity therein to thereby expose more readily the space between the top wall 30 and lip 34 to the edge 24 of the can opening 22.

In FIG. 8, the top wall 130 is formed convexly thereby eliminating the necessity of downwardly depending legs. Nevertheless, the lower edges of the top wall 300 extend downwardly beyond the edge of the sealing lip so that when the top wall edges engage the top of the can when the closure is inserted in place across the can opening the sealing lip is biased upwardly against the inner face ofthe can.

In FIGS. 9 to 14, other embodiments of downwardly depending body portions and sealing lips for engagement with the inner face 38 of the can top are illustrated. In each ofthese embodiments, the sealing lip or surfaces are closer to the top wall than the lower edge of each of the top wall depending legs. Thus, in FIG. 9, the body portion 320 may be either solid or cored as the particular requirements dictate. The interior sealing face a of the sealing lip 42a is disposed above the lower end of legs 40a and 42a. The sealing lip 34a projects outwardly from the body portion 32a by means ofa outwardly extending flange essentially as shown. The closure of this embodiment is inserted across the can opening 22 and removed therefrom in a similar manner to the previous described embodiments.

In the embodiment of closure 20b of FIG. 10, body portion 32b extends downwardly from the top Wall 3012 and also includes thereon an outwardly extending sealing lip 34b. The upwardly and outwardly bevelled wall 48b facilitates insertion of the body portion into the can interior. The downwardly and outwardly bevelled wall 50b is designed to engage with the edge 24 of the can top 26 when the closure is inserted in place and forced upwardly against the inner face 38 of the can top 26 by the upward force created incident to the engagement of the bottom lower edge of the legs 40b and 42b with the outer face 36 of the can top 26. Again, where desired, the body portion 32b may be cored.

In the embodiment of closure 20c of FIG. 11, the depending body portion 320 as extending outwardly therefrom a modified sealing lip 340, the sealing surface 50c of which need not be upwardly and outwardly extending but merely disposed as shown. However, in this embodiment as in the other embodiments herein, this sealing surface 50c is disposed above the lower extremity of the depending legs 40c and 426 of the top wall 300 in order to create a pressure seal with the inner face 38 ofthe can top 26.

In the embodiment of closure 20d of FIG. I2, the sealing lip 34d may be made relatively thinner as shown for added flexibility for insertion into the can opening and for responding to a greater extent to pressures within the can interior upon sealing of the can opening 22 by this closure 20d. In this connection, the sealing face 50d will flex upwardly into engagement with the inner face of the can top 26 as a result of this pressure. Under any circumstances, however, the sealing face 50d will be maintained in sealing relationship with the inner face 38 of the can top 26 because of the difference in elevation of this surface 50d and the bottom edge of the legs 40d and 42d of the top wall 30d. Where desired or necessary in order to prevent popping out of the closure, the peripheral surfaces of the body portion 32d between the top wall 30d and the sealing lip 34d may frictionally engage with the edges 24 of the can opening 22. As previously explained herein, this frictional engagement may also be provided for all of the other contemplated embodiments of closure of this invention.

In FIG. 13, the closure 20e is in substantially all respects similar to the closure of the previous embodiment. The sealing lip 344:, however, may be canted upwardly as shown to improve the pressure seal of the surface 50e with the inner face 38 of the can top 26. In addition, the upwardly extending face 48e of the sealing lip 340 facilitates the insertion of the lip through the can opening when the closure 20e is forced in place across the opening.

In FIG. 14, the closure 20f is provided with essentially the same top wall 30f and downwardly depending legs 40f and 42f. However, the body portion 32f assumes a bulbous configuration which may be readily obtained through blow-molding techniques. A number of circumferentially or peripherally extending sealing lips 34/ are provided on the body portion 32f above the lower edge of each of the legs 40f and 42] to cooperate with the underface of a can top in sealing the can contents.

In practice the closures of this invention may be fabricated from any number of moldable resinous materials. Desirable thermoplastic materials possess flexibility, resiliency and are ideally chemically inert and nontoxic in regard to the can contents. In addition to the types of materials suggested in my issued patent, I have found that KRATON 2000 series thermoplastic rubber polymers of styrene and butadiene commercially available and offered by Shell Chemical Company are particularly suitable. This type of material is not only moldable and quickly cured but also possess rubbery properties which are desirable for a closure of the type proposed by this invention.

Thus, the several aforenoted objects and advantages are most effectively attained. Although several similar preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.

We claim:

1. An essentially one-piece, molded, flexible and resilient can-top opening closure comprising a top wall constructed and arranged to extend over the opening;

an integral body portion depending downwardly from the top wall and having the same general peripheral configuration as that of the edges of the can top defining the top opening;

a sealing lip forming an integral part of the body portion spaced downwardly from the top wall and extending outwardly from the body portion, the lip being adapted to be inserted through the top opening along with the body portion, the lip having upper surfaces adapted to engage with the inner surfaces of the can top adjacent the top opening and adapted to form a seal therewith to retain the can contents in the can interior and prevent fluid leakage through the top opening past the closure;

said top wall having means presenting surfaces adapted to engage with the outer surface of the can top adjacent said opening whereupon the lip is adapted to be forced into firmer sealing engagement with the inner surface of the can top to effectively seal the contents of the can. the top wall including a downwardly facing edge which presents the surfaces adapted to engage with the outer surface of the can top adjacent said opening, the downwardly facing edge of the top wall is at a further distance from the top wall prior to insertion of the closure in the can top opening than the sealing lip to cause flexing of the top wall the inner surfaces of the can top and thereupon an upward biasing of the lip against the inner surfaces of the can top incident to such flexing.

2. The invention in accordance with claim 1 wherein the portion of the body portion between the top wall and the sealing lip corresponds in configuration to and outer peripheral edge of the sealing lip defining essentially the the can opening.

6. The invention in accordance with claim 5 wherein the base of can-top opening.

7. The invention in accordance with claim 1 wherein the sealing lip is flexible and when disposed in sealing relationship with the inner surfaces of the can top is adapted to increase the sealing relationship upon exposure to fluid pressure from within the can.

8. The invention in accordance with claim 1 wherein the sealing lip represents one of a plurality of such lips extending from a bulbous-shaped body portion.

9. The invention in accordance with claim 1 wherein the sealing lip forms part of a body portion that is bevelled outwardly to a location approximately intermediate its ends and then bevelled inwardly from this location downwardly to the lower end.

10. The invention in accordance with claim I wherein the sealing lip is on an upwardly projecting leg adapted to extend completely around the edge of the can top opening when disposed interiorly of the can, said leg depending upwardly from a radial flange which extends from the body portion.

11. An essentially one-piece, molded, flexible and resilient can-top opening closure comprising a top:

an integral body portion depending downwardly from the top and having the same general peripheral configuration as that of the edges of the can top defining the top openmg;

a sealing lip spaced downwardly from the top and extending outwardly from the body portion, the lip being adapted to be inserted through the top opening along with the body portion, the lip having upper surfaces adapted to engage with the inner surfaces of the can top adjacent the top opening and adapted to form a seal therewith to retain the can contents in the can interior and prevent fluid leakage past the closure, the sealing lip being an upwardy an outwardly depending member through the top opening into the canand arranged to extend over the opening;

an integral body portion depending downwardly from the top wall and having the same general peripheral configuration as that of the edges of the can top defining the top opening;

a sealing lip spaced downwardly from the top wall and extending outwardly from the body portion, the lip being adapted to be inserted through the top opening along with the body portion, the lip having upper surfaces adapted to engage with the inner surfaces of the can top adjacent the fluid leakage through the top opening passed the closure; said top wall presenting surfaces adapted to engage with the outer surface whereupon the lip is adapted to be forced into firmer sealing engagement with the inner surface of the can top to effectively seal the contents of the can, the top wall including a downwardly facing edge which presents the surfaces adapted to engage with the outer surface of the can top adjacent said opening, downwardly depending legs forming an integral part of the top wall adjacent its outer periphery which legs include said edge which presents said surfaces adapted to engage with the outer surface of the can top, and at least one interruption appearing between said legs which serves to facilitate the insertion and removal of the closure from the can-top opening. 13. The invention in accordance with claim 12 wherein the edge of the legs is at a further distance from the top wall than faces of the can top incident to such flexing.

14. The invention in accordance with claim 12 wherein two opposed interruptions appear between said legs which cooperate in facilitating the insertion and removal of the clo sure from the can top opening.

15. The invention in accordance with claim 12 wherein the sealing lip is an upwardly and outwardly depending member the body portion, the upper and can-top opening. 

1. An essentially one-piece, molded, flexible and resilient cantop opening closure comprising a top wall constructed and arranged to extend over the opening; an integral body portion depending downwardly from the top wall and having the same general peripheral configuration as that of the edges of the can top defining the top opening; a sealing lip forming an integral part of the body portion spaced downwardly from the top wall and extending outwardly from the body portion, the lip being adapted to be inserted through the top opening along with the body portion, the lip having upper surfaces adapted to engage with the inner surfaces of the can top adjacent the top opening and adapted to form a seal therewith to retain the can contents in the can interior and prevent fluid leakage through the top opening past the closure; said top wall having means presenting surfaces adapted to engage with the outer surface of the can top adjacent said opening whereupon the lip is adapted to be forced into firmer sealing engagement with the inner surface of the can top to effectively seal the contents of the can, the top wall including a downwardly facing edge which presents the surfaces adapted to engage with the outer surface of the can top adjacent said opening, the downwardly facing edge of the top wall is at a further distance from the top wall prior to insertion of the closure in the can top opening than the sealing lip to cause flexing of the top wall upon engagement of the lip with the inner surfaces of the can top and thereupon an upward biasing of the lip against the inner surfaces of the can top incident to such flexing.
 2. The invention in accordance with claim 1 wherein the portion of the body portion between the top wall and the sealing lip corresponds in configuration to the can-top opening and is dimensioned to be spaced from the can-top edges defining said opening around its entire periphery when the closure is placed over the can-top opening.
 3. The invention in accorDance with claim 1 wherein the portion of the body portion between the top wall and the sealing lip corresponds in configuration to the can-top opening and is dimensioned to be frictionally engaged with the can-top edges defining said opening around its entire periphery when the closure is placed over the can-top opening.
 4. The invention in accordance with claim 1 wherein the body portion is cored to thereby present an essentially tubular configuration.
 5. The invention in accordance with claim 1 wherein the sealing lip is an upwardly and outwardly depending member forming an integral part of the body portion, the upper and outer peripheral edge of the sealing lip defining essentially the same configuration as the can-top opening and being dimensioned to be larger than said opening such that upon insertion of the body portion into the can-top opening the lip is adapted to flex inwardly to clear the opening and upon insertion into the interior of the can the lip is adapted to flex outwardly and be biased against the inner surfaces of the can-top adjacent the can opening.
 6. The invention in accordance with claim 5 wherein the base of the lip adjacent the body portion is increased in thickness to thereby possess a lower degree of flexibility at this location to cooperate in preventing unintentional and permit only deliberate movement and removal of the closure from the can-top opening.
 7. The invention in accordance with claim 1 wherein the sealing lip is flexible and when disposed in sealing relationship with the inner surfaces of the can top is adapted to increase the sealing relationship upon exposure to fluid pressure from within the can.
 8. The invention in accordance with claim 1 wherein the sealing lip represents one of a plurality of such lips extending from a bulbous-shaped body portion.
 9. The invention in accordance with claim 1 wherein the sealing lip forms part of a body portion that is bevelled outwardly to a location approximately intermediate its ends and then bevelled inwardly from this location downwardly to the lower end.
 10. The invention in accordance with claim 1 wherein the sealing lip is on an upwardly projecting leg adapted to extend completely around the edge of the can-top opening when disposed interiorly of the can, said leg depending upwardly from a radial flange which extends from the body portion.
 11. An essentially one-piece, molded, flexible and resilient can-top opening closure comprising a top: an integral body portion depending downwardly from the top and having the same general peripheral configuration as that of the edges of the can top defining the top opening; a sealing lip spaced downwardly from the top and extending outwardly from the body portion, the lip being adapted to be inserted through the top opening along with the body portion, the lip having upper surfaces adapted to engage with the inner surfaces of the can top adjacent the top opening and adapted to form a seal therewith to retain the can contents in the can interior and prevent fluid leakage through the top opening past the closure, the sealing lip being an upwardly and outwardly depending member forming an integral part of the body portion, the upper and outer peripheral edge of the sealing lip defining essentially the same configuration as the can-top opening and being dimensioned to be larger than said opening such that upon insertion of the body portion into the can-top opening the lip is adapted to flex inwardly to clear the opening and upon insertion into the interior of the can the lip is adapted to flex outwardly and be biased against the inner surfaces of the can top adjacent the can opening, and the base of the lip adjacent the body portion being increased in thickness to thereby possess a lower degree of flexibility at this location to cooperate in preventing unintentional and permit only deliberate movement and removal of the closure from the can-top opening.
 12. An essentially one-piece, molded, flexible and resilient can-Top opening closure comprising a top wall constructed and arranged to extend over the opening; an integral body portion depending downwardly from the top wall and having the same general peripheral configuration as that of the edges of the can top defining the top opening; a sealing lip spaced downwardly from the top wall and extending outwardly from the body portion, the lip being adapted to be inserted through the top opening along with the body portion, the lip having upper surfaces adapted to engage with the inner surfaces of the can top adjacent the top opening and adapted to form a seal therewith to retain the can contents in the can interior and prevent fluid leakage through the top opening passed the closure; said top wall presenting surfaces adapted to engage with the outer surface of the can top adjacent said opening whereupon the lip is adapted to be forced into firmer sealing engagement with the inner surface of the can top to effectively seal the contents of the can, the top wall including a downwardly facing edge which presents the surfaces adapted to engage with the outer surface of the can top adjacent said opening, downwardly depending legs forming an integral part of the top wall adjacent its outer periphery which legs include said edge which presents said surfaces adapted to engage with the outer surface of the can top, and at least one interruption appearing between said legs which serves to facilitate the insertion and removal of the closure from the can-top opening.
 13. The invention in accordance with claim 12 wherein the edge of the legs is at a further distance from the top wall than the sealing lip to cause flexing of the top wall upon engagement of the lip with the inner surfaces of the can top and thereupon an upward biasing of the lip against the inner surfaces of the can top incident to such flexing.
 14. The invention in accordance with claim 12 wherein two opposed interruptions appear between said legs which cooperate in facilitating the insertion and removal of the closure from the can top opening.
 15. The invention in accordance with claim 12 wherein the sealing lip is an upwardly and outwardly depending member forming an integral part of the body portion, the upper and outer peripheral edge of the sealing lip defining essentially the same configuration as the can-top opening and being dimensioned to be larger than said opening such that upon insertion of the body portion into the can-top opening the lip is adapted to flex inwardly to clear the opening and upon insertion into the interior of the can the lip is adapted to flex outwardly and be biased against the inner surfaces of the can top adjacent the can opening.
 16. The invention in accordance with claim 15 wherein the base of the lip adjacent the body portion is increased in thickness to thereby possess a lower degree of flexibility at this location to cooperate in preventing unintentional and permit only deliberate movement and removal of the closure from the can-top opening. 